IN Collecting

Date: Thursday, February 10, 7pm. On view on Saturday, noon-5pm; Monday and Wednesday, 9am-4.30pm; Tuesday and day of sale, 9am-noon. Catalogue at www.sothebys.com

Need to know: It is estimated that as much as £188m will be spent at Christie’s and Sotheby’s on the second week of February as the two houses stage their flagship London sales of impressionist and modern art – but many believe the true “sale of the week” to be “Looking Closely”, an astounding private collection of 60 works by some of the greatest of all modern and contemporary masters.

The 200-page catalogue is replete with names such as Dalí, Giacometti, Chagall, Miró and Bacon and, remarkably, all the works belonged to a single individual. Sotheby’s is keeping the identity quiet, but it is widely believed to have been the low-profile Geneva-based collector George Kostalitz, who died last year. The works, valued at up to £54m, were acquired between the 1960s and 1990s – often directly from the artists or their dealers – and some have not been seen in public for decades.

Highlights: Despite the mighty stature of the featured artists, the majority of works on offer are of jewel-like size, having been bought for what Sotheby’s specialist Helena Newman describes as display on a “domestic scale”. Two portraits of Lucian Freud are included, the first being a 1964 triptych painted by Francis Bacon. The three canvases each measure just 14in by about 12in and the work was acquired direct from Bacon’s dealer, Marlborough Fine Art, 46 years ago. It is estimated at £7m-£9m, while a Freud self-portrait painted in 1952 when the artist was holidaying with author Ian Fleming at his Jamaican villa, Goldeneye, is tipped to realise up to £800,000.

Two other Freuds are also on offer: “Seated Figure”, at £1m-£1.5m, and “Frances Glory”, a tiny, 1988 oil of the artist’s granddaughter (£350,000-£450,000). A Salvador Dalí masterpiece in the form of a typically bizarre portrait of fellow surrealist Paul Eluard is estimated at up to £5m, while Alberto Giacometti’s depiction of his wife Annette in a red sweater is tipped to fetch up to £3m.

The two largest works on offer were specially commissioned from Marc Chagall in the early 1960s to decorate a room in the collector’s home. “David” and its companion painting, “Bethsabee”, are each estimated at £2.5-£3.5m, while two smaller Chagalls (“La Danse” and “La Musique”) that were also acquired direct from the artist could realise £6m between them.

The prices are well beyond the reach of most – but attend the pre-sale viewing regardless of whether or not you can afford to buy: it will serve as a lesson in quintessential connoisseurship.